Due to prospective stricter exhaust gas regulations, measures are being increasingly sought in order to be able to reduce the CO2 emission of internal combustion engines. A current measure for this is the reduction of consumption through downspeeding/downsizing combined with an exhaust gas turbocharging. The exhaust gas turbocharger generally has here a hydrodynamic sliding bearing, which is divided into an axial and radial bearing. In order to be able to further reduce the CO2 emission of turbocharged internal combustion engines, in particular an optimized mounting of a rotor in an exhaust gas turbocharger is helpful.
From WO 2011/154078 A1 a generic axial bearing is known for mounting a rotatable shaft, having a first bearing body which is fixedly connected to a bearing housing and having a second bearing body which rotates with the shaft. Here, the axial bearing has at least one oil pocket, arranged in circumferential direction, a wedge surface adjoining thereto, and a detent/bearing surface in turn adjoining thereto. The actual axial mounting of the rotatable shaft takes place via this wedge surface or respectively the detent/bearing surface by means of a pressure produced in the oil film.
In order to be able to also reduce the CO2 emission of turbocharged internal combustion engines in the long term, it is necessary in particular to be able to guarantee the bearing capacity of the axial bearing or respectively of the combined axial/radial bearing as far as possible over the entire lifespan and hence independent of wear. Through non-optimum ancillary conditions, for example deficient oil lubrication, oil temperatures which are too high or respectively thrust loads which are too high in transient processes, wear can occur to the axial bearing, which leads directly to a significant decrease of the loading capacity and hence of the bearing capacity of the axial bearing or respectively of the combined axial/radial bearing.